Rates & sources
Compound growth assumes reinvested returns and no platform fees. Past performance is not a guide to future returns.
Source: FCA — Investment basics — figures refreshed at the start of each tax year.
When to use this calculator
- Before choosing between saving, investing, or increasing your monthly contribution.
- When you want to compare best-case, base-case, and cautious return assumptions.
- When you need a quick projection before making a longer-term portfolio decision.
- When you are deciding how many more years of contributions are needed to reach a specific target balance.
- When you want to see whether starting earlier versus contributing more each month produces a bigger outcome.
A realistic New Zealand planning example
Use these sample inputs as a quick scenario test, then change one variable at a time to compare outcomes.
Your Current Age
35
Living Situation at 65
Single — living alone
Current Retirement Savings (NZ$)
NZ$15,000
Additional Annual Savings (NZ$)
NZ$15,000
After entering these figures, review annual nz super, weekly nz super and projected savings at 65 together rather than in isolation — each metric tells a different part of the story. Then rerun the tool with one input adjusted to see which variable has the biggest effect on all three outputs before you settle on a plan.
How to read your results
Annual NZ Super
Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.
Weekly NZ Super
Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.
Projected Savings at 65
Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.
4% Drawdown from Savings
Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.
Total Estimated Annual Income
This is the headline outcome of the calculation, but it is most useful when read alongside the supporting metrics below it rather than in isolation. Try changing one input at a time and watching how this total moves to understand which driver has the biggest impact.
Years to 65
Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.
Method & assumptionsAuthoritative sources
New Zealand Superannuation (NZ Super) is a universal government-funded pension paid to eligible New Zealanders from age 65. Unlike means-tested benefits, it is available to all who meet the residency requirements regardless of wealth, assets, or other income. The 2024/25 rates used in this calculator reflect three living situations: single living alone (NZ$25,539 per year), single sharing accommodation (NZ$23,487), and couples on a per-person basis (NZ$19,219 each). These rates are set annually by the New Zealand government and are generally adjusted in line with average wage growth to maintain their purchasing power over time. NZ Super is paid fortnightly directly to your bank account by Work and Income New Zealand after you apply, ideally a few weeks before your 65th birthday.
While NZ Super provides a meaningful income floor, most financial advisers recommend building additional savings through KiwiSaver or other investments to fund the retirement lifestyle you want. This calculator projects your savings growth using compound interest, then applies the widely used 4% annual drawdown rule to estimate a sustainable income from your nest egg. Adding that figure to your NZ Super total gives a rough estimate of annual retirement income. Keep in mind that this is an illustrative tool — actual investment returns vary, and inflation can erode purchasing power over time. For personalised retirement planning, consider speaking with a registered financial adviser or using the resources available through the government's Commission for Financial Capability (sorted.org.nz).
Common mistakes
- !Assuming a constant return without checking a more conservative growth rate.
- !Forgetting to include ongoing contributions, fees, or tax wrappers where relevant.
- !Focusing only on the final balance instead of the path required to reach it.
- !Ignoring the drag of platform fees or fund charges, which can reduce the real compounded return significantly over ten or more years.
- !Comparing ISA and general investment account projections without adjusting for the tax treatment of interest, dividends, or capital gains.
What to do next
- Test a cautious, expected, and optimistic growth rate instead of relying on a single projection.
- Compare this result with related savings or retirement tools before committing more money.
- Use the linked guides to understand which assumptions matter most over longer periods.
- Consider running the same figures in an ISA and a general account scenario to see how the tax treatment changes the outcome over ten or more years.
- If the projected balance falls short of your target, use the tool to work backwards — increase the monthly contribution until the result meets your goal.
Frequently asked
Use arrow keys to navigate items, Enter or Space to expand/collapse.
End-of-article next steps
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